Parcel singulation systems and methods

ABSTRACT

Parcel processing systems and methods. A method for singulating parcels includes receiving an input stream of a plurality of parcels including at least a leading parcel and a lagging parcel in a singulator system. The method includes updating position information of the leading parcel and the lagging parcel on a list. The method includes determining a leading speed of the leading parcel. The method includes determining an exit time of the leading parcel. The method includes setting a lagging speed of the lagging parcel according to the exit time of the leading parcel and a distance to an exit line of the lagging parcel. The method includes controlling conveyors to transport the leading parcel at the leading speed and to transport the lagging parcel at the lagging speed.

CROSS REFERENCE TO OTHER APPLICATION

This application includes subject matter in common with, but is otherwise unrelated to, commonly-assigned PCT application PCT/US2019/022446, filed Mar. 15, 2019, which is hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to an apparatus, system and method of organizing a disordered stream of articles into an ordered stream of single items spaced from each other for subsequent processing.

BACKGROUND OF THE DISCLOSURE

In high volume product handling operations, such as mail handling and similar processing, large quantities of items such as boxes, parcels packages or parts often varying widely in size, must be inducted into a sorter system. Typically, a feeder system for use in such processing areas takes a disordered stream of items fed to it on a conveyor and inducts the items onto a sorter system. The feeder system ideally should perform several functions. To the maximum extent possible, the feeder should singulate disordered items in order to present the articles to downstream processing equipment, such as a sorter, one at a time with some minimum specified spacing or separation between product items. The feeder system must also provide for the reading of destination information from the item so that the control system for the sort can track it through the system and sort it correctly. In the U.S., scannable bar codes are used for this purpose in automated systems. A third important function is intercepting and removing items which are non-machinable because they are too large, too heavy or the like from the system for special handling.

Singulation is an important first step in the handling and sorting of product items such as boxes, parcels or soft packages. Parcel singulation, as used herein, refers to the generation of a flow of discrete parcels having no two parcels abreast, stacked, or having a gap or lineal (in the direction of flow) separation less than some minimum value. In other words, singulation is a process whereby a randomly input stream of items moving on a conveyor system is separated into a stream of single items spaced from each other so that a downstream process can readily perform operations on each item one at a time. Mixed item streams are a particular challenge in that a mixed material stream may include packages that vary greatly in size and may be piled at random one upon another, forming agglomerates of packages that are difficult to detect and separate.

Presently, singulation is accomplished in two ways, by manual manipulation of material on bulk conveying lines and with mechanical singulators that rely on the mechanical characteristics of the material being singulated to generate an output stream in which the probability that each parcel is singulated is high. While manual operations can be relatively effective, they are costly; and high throughput, either continuous or in bursts, can exceed an individual's capacity, resulting in “doubles” or “multiples” (unsingulated output). Conventional mechanical singulation schemes vary widely in method, throughput, and error rates, but tend to be large (requiring a large amount of floor space) and subject to high error rates when handling material at the margins of the mechanical material specifications for which they are designed and/or tuned. They too tend to degrade in performance when they encounter heavy bursts of material flow.

Improved systems and methods are desirable.

SUMMARY OF THE DISCLOSURE

Disclosed embodiments relate to systems and methods for parcel processing and singulation, and other devices, systems, and methods as disclosed herein.

A method for singulating parcels includes receiving an input stream of a plurality of parcels including at least a leading parcel and a lagging parcel in a singulator system. The method includes updating position information of the leading parcel and the lagging parcel on a list. The method includes determining a leading speed of the leading parcel. The method includes determining an exit time of the leading parcel. The method includes setting a lagging speed of the lagging parcel according to the exit time of the leading parcel and a distance to an exit line of the lagging parcel. The method includes controlling conveyors to transport the leading parcel at the leading speed and to transport the lagging parcel at the lagging speed.

Various embodiments include a parcel singulator system having a plurality of conveyors, and a control system connected to control the plurality of conveyors, configured to perform processes as disclosed herein. Various embodiments include a non-transitory computer-readable medium storing executable instructions that, when executed, cause a control system of a parcel processing system to control the parcel processing system to perform methods as disclosed herein.

In various embodiments, the exit time is determined according to a distance to the exit line of the leading parcel and the leading speed. In various embodiments, the exit time is determined according to a distance to the exit line of the leading parcel, the leading speed, and a target gap. In various embodiments, the method is repeated for each of the plurality of parcels. In various embodiments, the lagging speed is determined to so that the lagging parcel reaches the exit line at a predetermined target gap distance behind the leading parcel. In various embodiments, the leading speed is a predetermined maximum speed at a time the leading parcel exits the singulator. In various embodiments, the exit line is a predetermined fixed point proximate to an exit of the singulator system. In various embodiments, the list also includes distance information for the leading parcel and the lagging parcel. In various embodiments, based on the leading speed and the lagging speed, the actual gap between the leading parcel and the lagging parcel is substantially equal to a target gap when the leading parcel and the lagging parcel exit the singulator. In various embodiments, the method is performed repeatedly and at a repetition rate sufficient that each of the plurality of parcels is adjusted substantially concurrently and continuously.

The foregoing has outlined rather broadly the features and technical advantages of the present disclosure so that those skilled in the art may better understand the detailed description that follows. Additional features and advantages of the disclosure will be described hereinafter that form the subject of the claims. Those skilled in the art will appreciate that they may readily use the conception and the specific embodiment disclosed as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. Those skilled in the art will also realize that such equivalent constructions do not depart from the spirit and scope of the disclosure in its broadest form.

Before undertaking the DETAILED DESCRIPTION below, it may be advantageous to set forth definitions of certain words or phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term “controller” means any device, system or part thereof that controls at least one operation, whether such a device is implemented in hardware, firmware, software or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this patent document, and those of ordinary skill in the art will understand that such definitions apply in many, if not most, instances to prior as well as future uses of such defined words and phrases. While some terms may include a wide variety of embodiments, the appended claims may expressly limit these terms to specific embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, wherein like numbers designate like objects, and in which:

FIGS. 1-3 schematically illustrate an apparatus in accordance with disclosed embodiments;

FIG. 4 illustrates a flowchart of a process in accordance with disclosed embodiments;

FIGS. 5 and 5A illustrate a raised belt continuous mode apparatus in accordance with disclosed embodiments;

FIG. 6 illustrates an alternate cam member in accordance with disclosed embodiments;

FIG. 7 illustrates a locally-clutched belt continuous mode apparatus in accordance with disclosed embodiments;

FIG. 8 illustrates a three-roller locally driven belt continuous mode apparatus in accordance with disclosed embodiments;

FIG. 9 illustrates a two-roller locally driven belt continuous mode apparatus in accordance with disclosed embodiments;

FIG. 10 illustrates a locally driven roller continuous mode apparatus in accordance with disclosed embodiments;

FIGS. 11 and 11A illustrate a drive for a fixed ratio belt continuous apparatus in accordance with disclosed embodiments;

FIG. 12 illustrates a fixed-ratio belt continuous apparatus in accordance with disclosed embodiments;

FIG. 13 illustrates a fixed ratio roller continuous apparatus in accordance with disclosed embodiments;

FIG. 14 illustrates a continuous conveying apparatus in accordance with disclosed embodiments;

FIG. 15 illustrates one example of a control system in accordance with disclosed embodiments; and

FIG. 16 depicts a block diagram of a data processing system with which an embodiment can be implemented.

DETAILED DESCRIPTION

The figures discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged device. The numerous innovative teachings of the present application will be described with reference to exemplary non-limiting embodiments.

A singulator as disclosed provides a means of generating a stream of single parcels, such as cartons, from a single layer bulk flow, accumulation, or batch containing one or more of said parcels. It is used to convert a bulk material flow or batch to a stream of single items with controlled spacing on a conveying device such as may be needed for some process such as reading or sorting. It accomplishes accurate separation of a wide spectrum of parcels using knowledge of parcel locations, speeds or other dynamics, and other information acquired by various means, computer processing using a straightforward algorithm, and a suitable conveying mechanism to selectively pull parcels piece-by-piece from a single layered, bulk accumulation of parcels, i.e. with an intelligent process.

A parcel singulator will take parcels moving in bulk at its input, and singulate and space those parcels so that, at its output, parcels will come out singulated with at least a minimum gap or pitch between each parcel. Before entering the singulator, parcels will be generally moving in bulk on the conveyor belt and their speed cannot be controlled individually.

Inside the singulator, the parcels will enter a stage of matrix belts, rollers, or other conveyor sections where each parcel's speed can be controlled individually. The singulator will track the position each parcel, from the time it enters the singulator until it exits, such as in a parcel list. The singulator can update the parcel list repeatedly to keep track of the position of each parcel. The parcel list can identify the position of each parcel, for example by using the coordinates of the vertices of each parcel. The parcel list can be sorted based on the distance from each parcel to the exit of the singulator. That is, in some case, the parcel having the edge or vertex that has the closest distance to the “exit line” of the singulator can be placed at the top of the list, with each following parcel on the list having the next smallest distance, so that the last parcel in the list has the farthest distance from the exit of the singulator. The “exit line” refers to the point considered in the disclosed processes as the exit of the singulator for the purposes of measurement calculations; the exit line can be, in various embodiments, any specific point such as a point at the end of a final conveyor of the singulator, a point on a subsequent conveyor after the conveyor system, or other fixed (but configurable) point at which the parcels are to be considered properly singulated and spaced.

Some systems perform the singulation process by parcel extraction. In such processes, the singulator system can monitor the bulk stream of parcels using the list to calculate the gap for each parcel.

These systems can then assign a state for each parcel, based on its gapping requirements, to be unsingulated, extracting, or singulated. If the gapping requirements are not met, then the parcel will be designated as “unsingulated.” If the gapping requirements are met, then the parcel will be designated as “singulated.” A parcel assigned as “extracting” is the next unsingulated parcel that has been selected by the system to become singulated.

These systems can then assign a speed to each parcel in the list. If the parcel is singulated, it will be assigned a high or maximum speed. Then the first unsingulated parcel in the list after the singulated parcel will be selected, designated “extracting,” and assigned a high speed. Then the rest of unsingulated parcels will be assigned to run at low or minimum speed. This speed differential separates the extracting parcel from the following unsingulated parcel(s) and so causes it to be effectively singulated.

Once the extracting parcel accelerates from low to high speed and becomes singulated, its state is changed to “singulated,” and the next unsingulated parcel will be selected for extraction.

Known techniques and systems for parcel handling are described, for example, in U.S. Pat. Nos. 6,484,886, 6,401,936, 6,471,044, 6,694,220, 6,629,018, 7,090,067, 7,233,840, 7,191,895, 7,413,071, 7,854,314, 8,079,462, 3,485,339, 5,092,451, 5,137,139, and 6,629,593, each of which is hereby incorporated by reference.

In a process as disclosed herein, in contrast to other systems, the dynamics of each parcel can be derived from or based on another parcel and the estimated time to exit from the singulator to optimally converge the actual dynamics to the target required dynamics of every parcels. In this way, the system can continually track the position and adjust the dynamics of each of the parcels as they are singulated. This allows the system to continuously monitor the parcel dynamics and to tune the speed of each conveyor portion to achieve the target dynamics.

In disclosed embodiments, the system can continue to correct or adjust the gapping between any two parcels even after the initial gapping requirements have been met, until the parcels exit the singulator, producing better accuracy and efficiency as compared to other approaches. A significant advantage of the disclosed techniques is that parcels are not singulated one at a time or forced the “wait” for other parcels to be singulated. Instead, parcel dynamics are effectively being adjusted concurrently for each parcel to optimally converge to the target dynamics in a continuous manner.

Further, disclosed embodiments allow for better flow of parcels within the singulator and at the exit and entry of the singulator. At the exit of the singulator, a system as disclosed herein produces a better, more consistent a flow of parcels, so that the exit of the singulator does not starve for parcels which would cause a drop in parcel throughput and efficiency.

Disclosed embodiments also provide a better input to the next “downstream” parcel processing stage after the singulator. In a parcel processing system incorporating a disclosed singulator, the next stage is enabled handle a higher throughput of parcels based on the more accurate gapping produced by the singulator, versus an input with lower throughput of parcels with less accurate gapping as produced by other system. This allows the direct efficiency improvements of the disclosed singulator stage to be carried to the next stage to improve efficiency across the entire parcel processing system.

In addition, disclosed embodiments provide increased accuracy even with a variation in the input flow of parcels. The techniques disclosed herein allow the input to the singulator to be less susceptible to the variation of flow of parcels, since the parcel gapping can be continuously monitored and adjusted as the singulation process is performed. This added accuracy and efficiency also allows the singulator to be configured at any time to achieve higher speed and performance.

According to disclosed embodiments, the target speed of every parcel is derived from and set according to the parcel in front of it and based on the distance and/or time projected for the parcel to exit the singulator. The system can first assign the first parcel in the list, which is the closest parcel to the exit of the singulator, with a maximum speed, such as the speed of the next stage after the singulator. The system can then calculate the estimated exit time for the leading parcel will be calculated based on its speed and the distance to cross the exit line plus its gapping requirements to the next lagging parcel. Then, based on the exit time of the leading parcel, the system can calculate the speed for the lagging parcel so that it reaches the exit line with the proper spacing from its leading parcel. The system can iterate thru the entire list of parcels, considering each parcel to be the “lagging” parcel with respect to the immediate previous parcel, regarded as the new “leading” parcel.

FIGS. 1-3 schematically illustrate an apparatus 10 (singulator system 10) in accordance with disclosed embodiments. FIG. 4 illustrates a process 400 in accordance with disclosed embodiments, discussed with reference to FIGS. 1-3. A singulator as disclosed herein may be implemented as part of a larger parcel processing system. The singulator and its components are referred to generically as the “system” below.

In a singulation process in accordance with disclosed embodiments, the speed to be set for each parcel can be derived from the parcel in front of it with respect to the time that it will exit the singulator at the exit line. In the examples of FIGS. 1-3, an exemplary exit line 30 is shown across takeaway conveyor 16, though, as described above, any fixed point in the singulator, at the exit of the singulator, or at any point after the singulator can be treated as the exit line.

The system first receives an input stream of parcels (402). This is typically a bulk stream of non-singulated parcels. For the specific example below, it is assumed that the input stream of parcels is de-stacked—that is, there is only one layer of parcels and none is stacked on top of the other. As used herein, a “parcel” refers to any parcel, package, mail piece, or other object processed as described.

In the example of FIG. 1, a stream of parcels 1-9 are conveyed via infeed conveyor 12 at entry velocity V_(e) onto singulator 14. Parcels 1-9 are conveyed from the singulator with takeaway conveyor 16 at exit velocity V_(x). The velocity boundary between V_(e) and V_(x) is schematically represented by line 18.

As shown in FIG. 1, accumulated parcels 1-9 are moved fully onto the singulator 14. Conveyors 20 on the singulator such as belts or rollers move the parcels 1-9 at entry velocity V_(e) until the singulator 14 is full or near full. V_(e) can then drop to zero, if necessary, as the already accumulated parcels are singulated. In various embodiments, the input velocity V_(e) can be set to be, for example, the average speed of any parcels still in the previous parcel processing stage. By this way the minimum, maximum, and average of the input speed to the system is much more efficient, which is therefore extremely beneficial to the parcel flow management and efficiency of the system.

Note that the conveyors 20 can be implemented by any combination of belts, rollers, or other physical structures that transport the parcels. In particular, in various embodiments, the conveyors 20 are implemented by a plurality of individually-controllable conveyor portions, such as individual belts or sets of rollers, so that the transport speed of any particular conveyor portion can be adjusted as described herein.

The system determines the presence and position information of a plurality of the parcels in the input stream of parcels (404). The determination can be initially detecting or thereafter updating this information. This can be performed using, for example, image information capturing devices as described herein or other detection systems. The while the presence of the parcels need only be detected for a first iteration of the process of FIG. 4, the position information can be detected and updated on subsequent iterations.

The system creates or updates a list of the detected plurality of the parcels in the input stream of parcels that includes the position information of each of the plurality of parcels (404). The list can include all of the parcels or only a subset of the parcels. For purposes of this discussion, the list includes at least a leading parcel and a lagging parcel. The list can be created, for example, when the parcels are first fed into and received by the singulator for a first iteration of the process of FIG. 4, then can be updated on subsequent iterations. The “list” can be in a linked list, array, or other data structure. The term “list” may be used herein without any limitation to a particular data structure. Each parcel's position can be tracked, for example, using the coordinates of the vertices of each parcel. The list can be sorted based on the distance of each parcel from the exit of the singulator, the exit line, or other fixed point. As any particular parcel is received in the singulator, it can be added to the list. Similarly, as any particular parcel exits the singulator, it can be removed from the list. In some embodiments, the list is not particular to the singulator itself, and is part of tracking information maintained for the parcels as they are processed throughout an overall parcel processing system. The list can include any of the other data discussed below, such as the current speed of any parcel, the current spacing between each parcel and any other parcel, the current distance between any parcel and the exit line, the exit time for any parcel, or otherwise. Of course, as described herein, much of this data does not need to be separately stored or tracked since it can be immediately derived from other data.

The “leading parcel” refers to the parcel that is ahead of the lagging parcel—that is, its position information indicates that it is closer to the exit of the singulator at takeaway conveyor 16 than is the lagging parcel, and generally refers to the parcel that is closest to the exit of the singulator. The leading parcel, when it is the actual closest parcel to the exit of the singulator, can be assigned a speed equal to exit velocity V_(x). The gapping requirements as described below can be calculated based on the leading parcel with respect to the lagging parcel.

The “lagging parcel” refers to the parcel behind the leading parcel—that is, its position information indicates that it is the next-closest parcel to the exit of the singulator, following the leading parcel. The speed of the lagging parcel, as described below, is derived from or based on the leading parcel to ensure that the leading parcel satisfies its spacing requirements. As may be seen from the discussion below, the speed of any given lagging parcel—that is, any parcel that has a leading parcel in front of it—can be calculated based in whole or in part on its particular leading parcel, regardless of where that lagging parcel is in the actual order of the parcels being processed.

As will be appreciated, any parcel, except for the parcels actually closest to the input of the singulator or to the exit of the singulator, may function as the lagging parcel in terms of setting its own speed based on the speed of its leading parcel, and may at the same time function as the leading parcel upon which the speed of the following lagging parcel is based.

In the examples of FIGS. 1-3, parcel 1 is the leading parcel and is also actually closes to the exit of the conveyor. Parcel 2 is chosen as the lagging parcel, since it is behind parcel 1 and there are no parcels in between them. Parcel 3 could likewise have been chosen, in this example, as the lagging parcel, since it also is behind parcel 1 and there are no parcels in between them. When using parcel 2 as the lagging parcel, in this example, it will be understood that the result of the process is to move parcel 2 ahead of parcel 3, so that in a next iteration, parcel 2 can be considered the leading parcel and parcel 3 can be considered the lagging parcel.

The “target gap” refers to the gap that is required for the leading parcel to meet its gapping requirements relative to the lagging parcel; it is the minimum required gap between the leading parcel and the lagging parcel.

The “actual gap” refers to the current actual gap that it is between the leading parcel and the lagging parcel. The actual gap can be calculated from the perspective of the leading parcel relative to the lagging parcel. Generally speaking, the singulator operates most efficiently when, at the exit, the parcels are moving at exit velocity V_(x), the speed of the next stage of the parcel processing system, and the actual gap between any two parcels matches the target gap.

The system determines the “leading speed” of the leading parcel (406). If the leading parcel is the first parcel in the list (the parcel nearest to the exit or other fixed point of the singulator), the leading speed can be a maximum speed, such as exit velocity V_(x), the speed of the next parcel-processing stage after the singulator. When the leading parcel is the first parcel on the list, if it is not already being transported at the maximum speed, determining the leading speed for that leading parcel can include assigning the maximum speed to that leading parcel and thereafter transporting that leading parcel at the maximum speed.

In other cases, for example when this process is iterating, the leading speed is known based on its previous determination as described below. In other cases, the leading speed can be determined according to the speed at which the conveyor portion that is transporting the leading parcel is operating.

Conceptually, as illustrated in FIG. 2 and when the leading parcel is the nearest parcel to the exit of the conveyor, the boundary between entry and exit velocities of the conveyors on the singulator has been extended forward to the trailing edge of the leading parcel 1. Leading parcel 1 can be accelerated to exit velocity V_(x) (which is determined to be the leading speed) and moves forward away from the remainder of the stationary batch of accumulated items. Note that while this example shows all the other parcels 2-9 still moving at entry velocity V_(e), as described below, each of the subsequent parcels 2-9 is a lagging parcel to some other parcel and can have its speed adjusted as described.

FIG. 2 also illustrates the difference between the gap and the pitch between two parcels. As illustrated, the actual gap between parcel 1 and parcel 2 is the lateral separation distance between the trailing edge (or point) of parcel 1 and the leading edge (or point) of parcel two. This may be compared to the actual pitch between parcel 1 and parcel 2, which is the lateral separation distance between the leading edge (or point) of parcel 1 and the leading edge (or point) of parcel two. The gap represents the distance between the trailing edge or point of one parcel and the leading edge or point of a following parcel, where the pitch represents the distance between the leading edges or points of successive parcels. In some case, where there is overlap between leading and lagging parcels, the gap may be a negative value, but the pitch will remain a positive value. Various embodiments may use the pitch between two parcels to determine speeds or other dynamics, while at the same time achieving a target gap between those parcels at the exit of the singulator.

Note that, while the example below is directed to ensuring that the parcels are singulated at substantially a target gap at the exit of the singulator, similar techniques can be applied for any measurement of target spacing, such as to ensure that the parcels are singulated at substantially a target pitch at the exit of the singulator or are singulated so that the centerlines/centerpoints of each parcel are spaced at substantially a target distance at the exit of the singulator.

The system can then determine the target gap between the leading parcel and the lagging parcel (408). In addition to being expressly loaded, retrieved, received, or calculated, the target gap may be preconfigured in the system based on the requirements of the downstream processes or equipment. Similarly, parcel pitch or other dynamics can be determined or preconfigured in the system based on the requirements of the downstream processes or equipment.

The system can then calculate, measure, or otherwise determine the exit time of the leading parcel (410). The “exit time” refers to the time it will take a parcel to reach the exit line plus the target gap (between it and its lagging parcel). Because the position of the leading parcel is known (for example, as maintained in the parcel list), the distance between its current position and the fixed-point exit line is also known. Similarly, the leading speed of the leading parcel has already been determined. So, in various embodiments, the system calculates the exit time of the leading parcel as:

${{Exit}\mspace{14mu}{Time}_{lead}} = \frac{{{Distance}\mspace{14mu}{to}\mspace{14mu}{Exit}\mspace{14mu}{Line}_{lead}} + {{Target}\mspace{14mu}{Gap}}}{{Leading}\mspace{14mu}{Speed}}$

The exit time will typically be measured in milliseconds or other fractions of a second, in a typical singulation operation, but can be greater than this if the singulator has a slower throughput.

Turning to FIG. 3, the system can determine the exit time from the location of leading parcel 1 and the exit line 30 based on the distance from the leading parcel 1 and the exit line 30, the target gap, and/or the current speed of leading parcel 1. The distance to the exit line 30 can be calculated by the leading edge/vertex of each parcel (that is, the distance to the point when the parcel first reaches the exit line), by the last edge/vertex of each parcel (that is, the distance to the point when the parcel completely passes the exit line), or with respect to any other point of each parcel, so long as the method of calculation is consistent for each parcel.

The system can then set a “lagging speed” of the lagging parcel based on its distance to the exit line and the exit time of its leading parcel (412), as

${{Lagging}\mspace{14mu}{Speed}} = \frac{{Distance}\mspace{14mu}{to}\mspace{14mu}{Exit}\mspace{14mu}{Line}_{lag}}{{Exit}\mspace{14mu}{Time}_{lead}}$

Note that the lagging speed calculation can include, in some cases, other factors. For example, based on the distance of the lagging parcel to the exit line at the time of the adjustment, a weighting factor can also be applied to ensure that the lagging parcel “catches up” or “falls back” to the target gap distance by the time the lagging parcel exits the singulator.

Note also that the lagging speed may be greater than the “maximum speed” discussed above, when the actual gap is greater than the target gap, so that the lagging parcel can catch up to the leading parcel at the target gap distance.

Further, in other cases, it will be understood that when the leading parcel exits the conveyor, the lagging parcel is no longer lagging at all and is only a leading parcel to its following parcel. In this case, the now-leading parcel can be assigned a speed regardless of its former leading parcel; for example, it can be assigned the exit velocity V_(x).

The system can then control the conveyors (or conveyor sections) to move the leading and lagging parcels at their respective speeds, adjusting each conveyor section speed as necessary (414). Doing so singulates the leading parcel from the lagging parcel and causes the actual gap between those parcels to approach, equal, or substantially equal the target gap. In various embodiments, based on the leading speed and the lagging speed, the actual gapping and dynamics between the leading parcel and the lagging parcel can be made substantially equal to a target gapping and dynamics when the leading parcel and the lagging parcel exit the singulator.

As the parcels are transported, the system can update the list with current position information or other information for each parcel (416). For example, the determined lagging speed for each parcel can be stored in the list, and that value can be used as the leading speed for calculating the lagging speed of the next parcel.

The process of FIG. 4 process can iterate thru the entire list of parcels, by repeating to 402 (if parcels are still being received) or 404, where the current lagging parcel will become the leading parcel and the next parcel in the list will become the lagging parcel.

Moreover, the process of FIG. 4 can be repeatedly or continually executed so that the speed of each lagging parcel is continually adjusted according to the speed of its leading parcel, by controlling the conveyors, to make the actual gap between any two parcels to be as close to the target gap as possible. For example, the iterations through the process of FIG. 4 can occur rapidly enough that the parcel speeds and other dynamics are effectively being adjusted continually and concurrently as the parcels are received into the singulator, singulated and gapped, and moved out of the singulator. In one non-limiting implementation example, each iteration through the process is performed in a 33 ms cycle.

The input speed of the stream of parcels can be controlled by the speed of the conveyor systems of the previous parcel processing stage. In various embodiments, the input speed of each parcel can be set to the speed of its leading parcel that is entering the singulator and can be adjusted according to any adjustments to the speed of its leading parcel. In other embodiments, the input speed can be set to the average speed of any parcels still in the previous parcel processing stage. By this way the minimum, maximum, and average of the input speed to the system is much more efficient, which is therefore extremely beneficial to the parcel flow management and efficiency of the system.

Disclosed processes provide a much more effective and efficient singulation process than processes that only adjust the speed of one parcel at a time, such as successively moving each parcel to the exit velocity while the others move are stationary or moving at only a slower constant velocity. In disclosed embodiments, as the stream of parcels enters the conveyor, the speeds of all received parcels are, in effect, immediately, concurrently, and constantly adjusted to achieve proper singulation with the target gap.

Another method for singulating parcels can include receiving an input stream of a plurality of parcels including at least a leading parcel and a lagging parcel in a singulator system. This method can include updating position and dynamics information of the leading parcel and the lagging parcel on a list. This method can include determining a leading speed and dynamics of the leading parcel. This method can include determining an actual and target gapping and dynamics between the leading parcel and the lagging parcel. This method can include determining the control/dynamics equations and relationships between the leading parcel and the lagging parcel, such as using the exit time, exit line distance, and other data and calculations as described herein. This method can include setting a lagging speed and dynamics of the lagging parcel derived from the equations and properties of the previous step to optimally converge the actual gapping and dynamics to the target gapping and dynamics. This method can include controlling conveyors to transport the leading parcel at the leading speed and to transport the lagging parcel at the lagging speed.

Another method for singulating and gapping parcels includes receiving an input stream of a plurality of parcels including at least a leading parcel and a lagging parcel in a singulator system. The method includes updating position and dynamics information of the leading parcel and the lagging parcel on a list. The method includes determining a leading speed and dynamics of the leading parcel. The method can include determining an actual gapping and dynamics between the leading parcel and the lagging parcel. The method includes determining the control and dynamics equations between the leading parcel and the lagging parcel, such as using the exit time, exit line distance, and other data and calculations as described herein. The method includes setting a lagging speed and dynamics of the lagging parcel derived from the control and dynamics equations between the leading and lagging parcels. For example, the lagging speed can be calculated as the quotient of the distance of the lagging parcel from the exit line to the exit time of the respective leading parcel. The method includes controlling conveyors to transport the leading parcel at the leading speed and to transport the lagging parcel at the lagging speed. Further, in some cases, parcels dynamics are being adjusted concurrently and at the same time to optimally converge to the target dynamics in a continuous manner.

In processes as disclosed herein, the speed of each parcel is derived from other parcels. In this way, the system maintains a holistic management of all parcels being singulated, tracking the position of each with respect to other parcels and the exit line and continually or repeatedly adjusting the speed of each parcel accordingly. This enables the system to continuously monitor of gapping and tune speeds to achieve the target gapping in the most efficient way according to the length of the singulator and its conveyor matrix. The system can keep correcting the gapping even after the gapping requirements have been initially met, until the parcels exit the singulator, achieving better accuracy and efficiency. Disclosed embodiments also allow for better flow of parcels within the singulator and at the exit and entry of the singulator. At the exit of the singulator, disclosed processes produce a more consistent, efficient throughput so that the exit of the singulator does not starve for parcels which would cause a drop in parcel throughput and efficiency. This also provides a better input to the next stage after the singulator, since the next stage can handle a higher throughput of parcels with more accurate gapping versus an input with lower throughput of parcels with less accurate gapping. In this way, disclosed processes allow the efficiency of the singulator stage to be carried to the next stage to bring the efficiency up across the entire parcel processing system. Further, processes as disclosed herein the input of the singulator to be less susceptible to the variation of flow of parcels at the entry of the singulator. The added accuracy and efficiency produced by the processes disclosed herein allow the singulator to be configured at any time to achieve higher speed and performance.

Referring now to FIGS. 5 and 5A, a raised belt continuous mode apparatus 60 corresponding to one embodiment of the conveyors 20 is disclosed. In embodiments of this type, narrow slider belts 62, supported by a flat, low-friction surface, and driven at one velocity, either entry velocity V_(e) or exit velocity V_(x), are interleaved with narrow belts 64, such as elastic “O” belts, driven at the other velocity. The second set of belts 64 are wrapped in serpentine fashion around pairs of rollers 66 as shown in FIG. 5. The upper surface of a serpentine belt is normally slightly below that of the slider belts 62. Engagement of the serpentine belt with the bottom surface of conveyed material is achieved by raising a selected roller pair so that the upper surface 78 of belt 64 is raised slightly above the surface of the adjacent slider belts 62. In the illustrated embodiment, columns 70 are each provided with an inclined face 72 that is engaged by an inclined surface 76 of cam member 74 as the member is advanced, raising the column. This raises the pair of rollers 66 associated with the column 70 until the upper surface of belt 64 is above the adjacent slider belts 62. Actuating the cam member 74 to raise roller pairs 66 can be achieved by electrical means, such as a solenoid 80, a pneumatic or hydraulic cylinder, a motor using a screw-type drive or other mechanical means. As best shown in FIG. 5A, the parcel being transported using a raised belt embodiment may be moved by raising a pair or pair(s) of rollers 66, each corresponding to longitudinal column or column(s) n consisting of m roller pairs. Thus, only n actuators are required as opposed to m×n, where m represents the number of lateral rows of columns.

FIG. 6 illustrates an alternate cam member 82 for use in connection with the embodiment illustrate in FIG. 5 is illustrated. As shown, cam members 84(a)-84(c) are arranged along the length of tube 86, each tube corresponding to a successive column or columns 70 and each cam member corresponding to a row. As will be appreciated, as the tube 86 is rotated in the direction indicated by arrow 88, cams 84(a)-84(c) will successively engage corresponding columns, raising the corresponding roller pair or pairs. As will also be appreciated, when the tubes 86 are rotated through 360.degree. to the location designated by arrows 90, to the cams 84(a)-84(c) will simultaneously disengage allowing all of the columns corresponding to belt 64 to lower at one time. Tubes 86 may be actuated and rotated with an electric solenoid or motor, a hydraulic or pneumatic cylinder or other mechanical or electrical devices, depending upon the application.

FIG. 7 illustrates a locally-clutched belt continuous mode apparatus 100 corresponding to another embodiment of conveyors 20. In this embodiment, the bed or upper surface of the singulator 34 is populated with an array or matrix of short belts 108. Each belt 108 is wrapped around two idler rollers 102 that the conveyed material, and two clutched drive rollers, 104 and 106. Each of the drive rollers 104 and 106 is mounted on a shaft, 110 and 112, respectively, rotating at a speed associated with either entry or exit velocity. Clutches 114 and 116 corresponding to drive rollers 104 and 106 are selectively engaged or disengaged to cause the belt to move at the appropriate velocity. For example, drive roller 104 may be configured to operate at a constant velocity whereas drive roller 106 may be configured to operate at a controlled speed. The drive for each belt 108 is intelligently selected, either constant velocity or controlled velocity, to move one or more parcels downstream at the constant velocity while retarding others as required to achieve a downstream flow of single parcels separated by a controlled target gap as discussed herein. As used herein, the terms “intelligence” and “intelligently” refers generally to the use of a means of capturing and generating image information for parcels such as a camera or vision system or an array of physical measuring devices such as photocells, pressure sensors, and similar devices, information that is transformed via suitable algorithms into location and other information for individual parcels and subsequently used by a computer or microprocessor to control the operation of discrete elements such as apparatus 100.

FIG. 8 shows a three-roller locally driven belt continuous mode apparatus 120, comprising another alternative embodiment of conveyors 20, is shown. In this embodiment, the singulator bed is populated with an array of short belts 122 that support conveyed material. Each belt 122 is wrapped around two idler rollers 124 that support the weight of the conveyed material and a third idler roller 126 well below the surface of the bed. As shown, idler rollers 124 and 126 are mounted on a frame 132. Frame 132 is in turn pivotable around drive engagement pivot pin 134. A solenoid 136 or similar actuator is coupled to a lower section of frame 132 in order to selectively pivot the frame. Drive rollers 128 and 130 are mounted adjacent to lower idler roller 126 and are operated at rotational speeds corresponding to entry velocity V_(e), exit velocity V_(x), or other speed controlled as described herein.

As will be appreciated, actuator 136 may selectively pivot frame 132 causing belt 122 to be engaged by either of drive rollers 128 and 130, surfaces of which are moving at either entry velocity or exit velocity, where the belt wraps around idler roller 126. Thus, the drive for each belt 122 maybe intelligently selected, corresponding to either entry velocity V_(e), exit velocity V_(x), or other speed controlled as described herein, to move one or more parcels downstream while retarding others as required to achieve a downstream flow of single parcels separated by a controlled target gap as discussed herein.

FIG. 9 illustrates a two-roller locally driven belt continuous mode apparatus corresponding to yet another embodiment of conveyors 20. The apparatus 150 is in all respects similar to the apparatus shown in FIG. 8 with the exception that the third idler belt 126 of apparatus 120 is omitted. Instead, each belt 122 is wrapped around two idler rollers 124 that support the weight of the conveyed material. Where belt 122 wraps around each of the idler rollers 124 the belt may be selectively engaged either of drive rollers 128 and 130 whose surfaces is moving at entry velocity V_(e), exit velocity V_(x), or other speed controlled as described herein, by means of actuator 136 pivoting frame 132.

FIG. 10 illustrates a locally driven roller continuous mode apparatus 150 corresponding to an additional embodiment of conveyors 20. In this embodiment, the bed of the singulator is populated with an array of rollers 152 that support conveyed material. Each roller 152 is moveable for engagement with either drive roller 128 whose surface is moving at entry velocity V_(e) (or other speed) or with a drive roller 128, whose surface is moving at exit velocity V_(x) (or other speed). Thus, the drive for each locally driven roller apparatus 160 may be intelligently selected, corresponding to entry velocity V_(e), exit velocity V_(x), or other speed controlled as described herein, to move one or more parcels downstream while retarding others as required to achieve a downstream flow of single parcels separated by a controlled target gap as discussed herein.

FIGS. 11 and 11A illustrate a drive 170 for a fixed ratio belt continuous apparatus. In this embodiment a planetary mechanism, gear or friction engaged, and two clutches in a drive roller are used to generate two velocities from a single drive shaft. The planetary drive includes drive shaft 178, frame 182, an outer rotational element (gear or roller) 172, a clutch engagement element 174, clutch pads 190, an inner rotational element (gear or roller) 188 coupled to drive shaft 178, middle rotational elements (gears or rollers) 186 and a planetary middle rotational element (axles and dual speed roller). An actuator such as a solenoid or hydraulic or pneumatic cylinder 180 actuates the clutch for engagement between the outer planetary element and the middle element for shaft velocity or between the outer planetary element to the frame for low velocity as shown in FIG. 11A.

FIG. 12 illustrates a fixed-ratio belt continuous apparatus that is yet another embodiment of conveyors 20 for use in connection with the singulator of the invention. Conveying belt 202 passes over a pair of idler rollers 204 and dual-velocity drive roller 206, all of which are mounted in a roller/belt frame 210. Dual-velocity drive roller 206 includes a drive shaft 212 for coupling the drive roller to a two-speed drive, such as the planetary drive illustrated in FIGS. 11 and 11A. In this embodiment, planetary mechanism 170 (gear or friction engaged) is used to generate two velocities from a single drive shaft. Thus, each fixed-ratio belt apparatus 170 maybe intelligently driven at one of the two speeds corresponding to the outputs of the planetary drive 170 by means of actuator 180, to move one or more parcels downstream while retarding others as required to achieve a downstream flow of single parcels separated by a controlled target gap.

FIG. 13 illustrates a fixed ratio roller continuous apparatus 220 corresponding to a further embodiment of conveyors 20. The apparatus includes a dual-velocity drive roller 222 mounted in a supporting structure 206. The drive roller 222 includes a drive shaft 204 that maybe coupled to a two-speed drive such as the planetary apparatus illustrated in FIGS. 11 and 11A and operated in the same fashion described above in connection with the fixed-ratio belt apparatus 200 illustrated in FIG. 12.

Turning now to FIG. 14, there is illustrated a continuous conveying apparatus 230 for use as an embodiment of conveyors 20. As shown, the apparatus 230 includes extendable belts 232 and 234 operating at entry velocity V_(e), exit velocity V_(x), or other speed controlled as described herein. As will be appreciated, embodiments of the invention using this type of conveyors are based not on an array of discrete points (FIG. 23), but on a set of long, narrow columnar structures that support two narrow in-line belts, one driven at entry velocity and the other at exit velocity.

Each of belts 232 and 234 pass around idler rollers 252, end rollers 254 that maybe drive rollers, and through a series of tension rollers 237 and idler rollers 235 in a serpentine path. Tension rollers are 237 are mounted in a moveable frame 236 that is spring-loaded by spring 238 to allow for take up and let out of the belts 232 and 234 as the support 250 is moved longitudinally by means of screw drive 246. Each of belts 232 and 234 is supported by a slider belt support 240 which as shown includes overlapping sections 242 and 244 that may be moved relative to each other by screw drive 246. Screw drive 246 is actuated by screw drive motor 248 which in turn is intelligently controlled to vary the position of support 250 to move one or more selected parcels downstream in the manner discussed in connection with FIGS. 7-12 to achieve a downstream flow of single parcels separated by a controlled target gap.

FIG. 15 schematically illustrates one example of a control system 270 for use in connection with the selective advance intelligent singulator. As shown, a feed conveyor 272 upstream of singulator 274 is equipped with image information capturing devices (detection system) such as one or more cameras 280, and/or vertical and/or horizontal sensors 282 and/or an array of pressure sensing devices 284, as desired. These or similar devices are utilized to capture image information corresponding to a stream of disordered parcels to be singulated.

The captured image information is transmitted to a computer or microprocessor 286 where the information is interpreted and/or transformed using preprogrammed algorithms. Alternatively, this data collection means by be replaced using pallet layer placement information in conjunction with a data base.

As shown, singulator 274 is represented as an array of discreet points or locations 278, each of which correspond to a conveyor 20. The various conveying devices illustrated herein and discussed in connection therewith may be advantageously utilized at each of the locations 278 as conveyors. Multiple devices of the type shown herein may also be utilized as conveyors 20 in a similar fashion.

Each conveyors 20 positioned at locations 278 may be discretely and intelligently controlled by microprocessor 286 so as to vary the speed or parcels being transported across the singulator 274 and transform a disorganized stream of material into an orderly flow of single parcels separated by a controlled target gap as discussed herein. Additional cameras 280 and/or sensors 282, 284 may also be used in connection with the singulator 274 to monitor and control the operation of the system. It will also be appreciated that while various belt and roller conveying devices have been disclosed in connection with the invention, it is contemplated that other material transporting devices may also be used, as well as variations of the belt and roller devices disclosed herein.

FIG. 16 depicts a block diagram of a data processing system 1600 with which an embodiment can be implemented, for example as a system for implementing any of the devices, methods, or systems described herein, and can be configured to perform processes as described herein, and in particular can be used as the control system for a parcel processing system as described herein. In particular, data processing system 1600 can perform any functions or include any additional devices as described above with respect to FIG. 15.

The data processing system depicted includes a processor 1602 connected to a level two cache/bridge 1604, which is connected in turn to a local system bus 1606. Local system bus 1606 may be, for example, a peripheral component interconnect (PCI) architecture bus. Also connected to local system bus in the depicted example are a main memory 1608 and a graphics adapter 1610. The graphics adapter 1610 may be connected to display 1611.

Other peripherals, such as local area network (LAN)/Wide Area Network/Wireless (e.g. WiFi) adapter 1612, may also be connected to local system bus 1606. Expansion bus interface 1614 connects local system bus 1606 to input/output (I/O) bus 1616. I/O bus 1616 is connected to keyboard/mouse adapter 1618, disk controller 1620, and I/O adapter 1622. Disk controller 1620 can be connected to a storage 1626, which can be any suitable machine usable or machine readable storage medium, including but not limited to nonvolatile, hard-coded type mediums such as read only memories (ROMs) or erasable, electrically programmable read only memories (EEPROMs), magnetic tape storage, and user-recordable type mediums such as floppy disks, hard disk drives and compact disk read only memories (CD-ROMs) or digital versatile disks (DVDs), and other known optical, electrical, or magnetic storage devices. Storage 1626 can store, for example, the list 1650 discussed above, any executable instructions or other code 1652, and any other data 1654 useful in performing the processes described herein, other parcel-processing processes, or other processes, including but not limited to gap data, position or distance data 1656, pitch data, speed data 1658, parcel identification data, centerline data, centerpoint data, time data 1660, or other data, whether or not specifically illustrated.

I/O adapter 1622 can be connected to control or communicate with parcel processing equipment 1628, which can include transport devices or conveyors, sensors, booms, sorters, gappers, singulators, diverters, recirculators, or any other hardware disclosed herein or other hardware devices for processing parcels in accordance with the various embodiments described herein.

Also connected to I/O bus 1616 in the example shown is audio adapter 1624, to which speakers (not shown) may be connected for playing sounds. Keyboard/mouse adapter 1618 provides a connection for a pointing device (not shown), such as a mouse, trackball, trackpointer, etc. as well as for keyboard or other user entry devices. In particular, a system as illustrated in FIG. 16 can receive any user interaction or user entry of relevant data, such as a desired (target) spacing, gapping, or pitch distance, a selection of whether the singulation should be based on gap, pitch, centerline/centerpoints, or any other input or configuration information useful for the processes described herein.

Those of ordinary skill in the art will appreciate that the hardware depicted in FIG. 16 may vary for particular implementations. For example, other peripheral devices, such as an optical disk drive and the like, also may be used in addition or in place of the hardware depicted. The depicted example is provided for the purpose of explanation only and is not meant to imply architectural limitations with respect to the present disclosure.

A data processing system in accordance with an embodiment of the present disclosure includes an operating system employing a graphical user interface. The operating system permits multiple display windows to be presented in the graphical user interface simultaneously, with each display window providing an interface to a different application or to a different instance of the same application. A cursor in the graphical user interface may be manipulated by a user through the pointing device. The position of the cursor may be changed and/or an event, such as clicking a mouse button, generated to actuate a desired response.

One of various commercial operating systems, such as a version of Microsoft Windows™, a product of Microsoft Corporation located in Redmond, Wash. may be employed if suitably modified. The operating system is modified or created in accordance with the present disclosure as described.

LAN/WAN/Wireless adapter 1612 can be connected to a network 1630 (not a part of data processing system 1600), which can be any public or private data processing system network or combination of networks, as known to those of skill in the art, including the Internet. LAN/WAN/Wireless adapter 1612 can also communicate with packages as described herein and perform other data processing system or server processes described herein. Data processing system 1600 can communicate over network 1630 with one or more server systems 1640, which are also not part of data processing system 1600, but can be implemented, for example, as separate data processing systems 1600. A server system 1640 can be, for example, any of the other systems described herein, and so indicates how systems can intercommunicate over network 1630.

It is important to note that while the disclosure includes a description in the context of a fully functional system, those skilled in the art will appreciate that at least portions of the mechanism of the present disclosure are capable of being distributed in the form of a computer-executable instructions contained within a machine-usable, computer-usable, or computer-readable medium in any of a variety of forms to cause a system to perform processes as disclosed herein, and that the present disclosure applies equally regardless of the particular type of instruction or signal bearing medium or storage medium utilized to actually carry out the distribution. Examples of machine usable/readable or computer usable/readable mediums include: nonvolatile, hard-coded type mediums such as read only memories (ROMs) or erasable, electrically programmable read only memories (EEPROMs), and user-recordable type mediums such as floppy disks, hard disk drives and compact disk read only memories (CD-ROMs) or digital versatile disks (DVDs). In particular, computer readable mediums can include transitory and non-transitory mediums, unless otherwise limited in the claims appended hereto. For example, various embodiments include systems, methods, and computer-readable media.

Although an exemplary embodiment of the present disclosure has been described in detail, those skilled in the art will understand that various changes, substitutions, variations, and improvements disclosed herein may be made without departing from the spirit and scope of the disclosure in its broadest form. In the processes described above, various steps may be performed sequentially, concurrently, in a different order, or omitted, unless specifically described otherwise. Similarly, various elements of the systems and apparatuses described herein can be duplicated, rearranged, or omitted in various embodiments, unless described or claimed otherwise.

None of the description in the present application should be read as implying that any particular element, step, or function is an essential element which must be included in the claim scope: the scope of patented subject matter is defined only by the allowed claims. Moreover, none of these claims are intended to invoke 35 USC § 112(f) unless the exact words “means for” are followed by a participle. 

What is claimed is:
 1. A method for singulating parcels, comprising: receiving an input stream of a plurality of parcels including at least a leading parcel and a lagging parcel in a singulator system; updating position information of the leading parcel and the lagging parcel on a list; determining a leading speed of the leading parcel; determining an exit time of the leading parcel; setting a lagging speed of the lagging parcel according to the exit time of the leading parcel and a distance to an exit line of the lagging parcel; and controlling conveyors to transport the leading parcel at the leading speed and to transport the lagging parcel at the lagging speed.
 2. The method of claim 1, wherein the exit time is determined according to a distance to the exit line of the leading parcel and the leading speed.
 3. The method of claim 1, wherein the exit time is determined according to a distance to the exit line of the leading parcel, the leading speed, and a target gap.
 4. The method of claim 1, wherein the method is repeated for each of the plurality of parcels.
 5. The method of claim 1, wherein the lagging speed is determined to so that the lagging parcel reaches the exit line at a predetermined target gap distance behind the leading parcel.
 6. The method of claim 1, wherein the leading speed is a predetermined maximum speed at a time the leading parcel exits the singulator system and an entry speed of each of the plurality of parcels at an entry to the singulator system is set to an average speed of parcels in a previous parcel processing stage.
 7. The method of claim 1, wherein the exit line is a predetermined fixed point proximate to an exit of the singulator system.
 8. The method of claim 1, wherein the list also includes distance information for the leading parcel and the lagging parcel.
 9. The method of claim 1, wherein, based on the leading speed and the lagging speed, the actual gap between the leading parcel and the lagging parcel is substantially equal to a target gap when the leading parcel and the lagging parcel exit the singulator system.
 10. The method of claim 1, wherein the method is performed repeatedly and at a repetition rate sufficient that each of the plurality of parcels is adjusted substantially concurrently and continuously.
 11. A parcel singulator system, comprising: a plurality of conveyors, and a control system connected to control the plurality of conveyors, wherein the control system is configured to: receive an input stream of a plurality of parcels including at least a leading parcel and a lagging parcel in a singulator system; update position information of the leading parcel and the lagging parcel on a list; determine a leading speed of the leading parcel; determine an exit time of the leading parcel; set a lagging speed of the lagging parcel according to the exit time of the leading parcel and a distance to an exit line of the lagging parcel; and control conveyors to transport the leading parcel at the leading speed and to transport the lagging parcel at the lagging speed.
 12. The parcel singulator system of claim 11, wherein the exit time is determined according to a distance to the exit line of the leading parcel and the leading speed, or is determined according to a distance to the exit line of the leading parcel, the leading speed, and a target gap.
 13. The parcel singulator system of claim 11, wherein the control system is configured to repeat each of the actions for each of the plurality of parcels.
 14. The parcel singulator system of claim 11, wherein the lagging speed is determined to so that the lagging parcel reaches the exit line at a predetermined target gap distance behind the leading parcel.
 15. The parcel singulator system of claim 11, wherein the leading speed is a predetermined maximum speed at a time the leading parcel exits the singulator system and an entry speed of each of the plurality of parcels at an entry to the singulator system is set to an average speed of parcels in a previous parcel processing stage.
 16. The parcel singulator system of claim 11, wherein the exit line is a predetermined fixed point proximate to an exit of the singulator system.
 17. The parcel singulator system of claim 11, wherein the list also includes distance information for the leading parcel and the lagging parcel.
 18. The parcel singulator system of claim 11, wherein, based on the leading speed and the lagging speed, the actual gap between the leading parcel and the lagging parcel is substantially equal to a target gap when the leading parcel and the lagging parcel exit the singulator system.
 19. The parcel singulator system of claim 11, wherein the control system is configured to execute the sequence of actions repeatedly and at a repetition rate sufficient that each of the plurality of parcels is adjusted substantially concurrently and continuously.
 20. A non-transitory computer-readable medium storing executable instructions that, when executed, cause a control system of a parcel singulator system to: receive an input stream of a plurality of parcels including at least a leading parcel and a lagging parcel in a singulator system; update position information of the leading parcel and the lagging parcel on a list; determine a leading speed of the leading parcel; determine an exit time of the leading parcel; set a lagging speed of the lagging parcel according to the exit time of the leading parcel and a distance to an exit line of the lagging parcel; and control conveyors to transport the leading parcel at the leading speed and to transport the lagging parcel at the lagging speed. 